I also found the online solution involving some needle nose pliers - Did the procedure and the 15-22 has been problem free ever since.

I ALMOST tried it but I had just got the gun brand new and I was leaving to go offshore so I figured I'd let them give it a shot. Just hope it's home when I get there. Any idea how long repairs are taking these days?

Just purchased a 15-22 because I like to shoot and ammo is just too damn expensive right now. It seems Ike a decent rifle for a little over $400. But I'm having trouble with it not fully ejecting. I was wondering if this gun likes a certain ammo better than others. Anyone have any experience with this?

Since I had an issue with mine in 2009 with Remington ammo sending the extractor, spring and pin apart. I re-assembled and did the review and since then Blazer .22LR 40 gr ammo, did fire some Federal Match - was not happy with Federal ammo.

Forgot to mention, M&P 15-22 is picky on scopes, had a Simmons, that failed, attached a Sightmark Riflescope 8.5-25x50, loved it! A year later, removed the Sightmark for my Mossberg and put on a Nikon scope, the issues kept coming.

I finally broke down and purchased the same Sightmark Riflescope. Problem fixed.

Got it back yesterday from S&W. That was super quick! Exactly 2 weeks from the time FedEx picked it up from my house till the time I got it back. Unfortunately I won't be home for a while so I can't check to see if its fixed.

I'll quote from the manual:
"Through our testing, Smith & Wesson has found that there are several brands and types of .22LR ammunition that do not perform consistently or reliably. Consequently, Smith & Wesson DOES NOT RECOMMEND that the following brands or types of .22LR ammunition be used in your M&P 15-22."

Also if you have the Performance Center Model it is equipped with a .22LR Lanley semi-auto match chamber which does not accommodate CCI Stinger brand ammunition. WARNING: Never use CCI .22LR Stinger brand ammunition in your M&P 15-22 Performance Center Model Rifle.

OK on to what they DO recommend.

"Based on the design and action of the M&P 15-22, Smith & Wesson recommends that you use the following brands and types of .22LR ammunition for optimal performance in your M&P 15-22 rifle".

I have been using the CCI Mini-Mag and Aguila Super Extra Std. Velocity with no issues at all. I did by a couple of the 33rd after market mags and they do not work that well. The 25rd S& W mag works every time. I will be looking for a couple more of them when the prices come down.

Sorry for the long post but I thought it might be a help to those wondering about what ammo to use.